Setting of automatic call acceptance time, only used if 'headset' in systemPhoneAudioFac is enabled(1) and a function-key 'autoanswer' is configured and active on the system phone. For NG phones there are new values available, marked with *: immediately: phone immediately accepts calls. sec-5: phone accepts calls after 5 seconds ringing. sec-10: phone accepts calls after 10 seconds ringing. sec-15: *phone accepts calls after 15 seconds ringing (only for NG phones). sec-20: *phone accepts calls after 20 seconds ringing (only for NG phones).